A purported spokesman for Boko Haram, an Islamic sect, claimed responsibility for the bombing of a church outside the capital Abuja and other violence which stoked fear and anger in Africa’s most populous nation.

Nigeria’s national security adviser blamed the group for the horrific attacks that saw worshippers killed as they were leaving church and burnt inside their cars.

In some of the most horrific scenes, victims at the church outside the capital — where 35 were killed — ran toward a priest with dying pleas, including one man who was mortally wounded.

The series of attacks drew condemnation from the Vatican, the White House and several western countries as Nigerian President Goodluck Jonathan pledged to bring the perpetrators to justice.

“These acts of violence against innocent citizens are an unwarranted affront on our collective safety and freedom,” Jonathan said in a statement. “Nigerians must stand as one to condemn them.”

Nigerian authorities were unable to prevent the latest attacks despite military crackdowns and claims of arrests of Boko Haram members in the country, roughly divided between a mainly Muslim north and mostly Christian south.

One attack Sunday saw a suicide bomber trying to ram a military convoy in front of a secret police building in the northeastern city of Damaturu. The attack killed the bomber and three security agents.

Other attacks included a bomb blast outside an evangelical church in the central city of Jos that killed a policeman, said a spokesman for the governor.

Another explosion targeted a church in the northeastern area of Gadaka on Christmas Eve, but no one was reported killed, while two other blasts hit the northeastern city of Damaturu on Christmas Day, including the suicide bombing.

The worst of the carnage, however, was reserved for the St. Theresa Catholic Church in Madalla, outside Abuja.

National Security Adviser Owoye Azazi said in a statement that Boko Haram members threw improvised explosive devices from a moving vehicle.

Benjamin Ekwegbali, a social worker at the church, described scenes of horror and destruction, with “corpses littered everywhere.”

He described a “very loud sound. It shook everywhere. When I looked back to see what happened, it was difficult to see anything. Everywhere was dark. Fire was burning.”

A Vatican spokesman labeled the attack an act of “blind hatred” and the United States and Great Britain were among Western nations that voiced outrage.

“We condemn this senseless violence and tragic loss of life on Christmas Day,” White House press secretary Jay Carney said in a statement.

Boko Haram has claimed responsibility for scores of attacks in Nigeria, including the August suicide bombing of UN headquarters in Abuja that killed at least 24 people.

Violence blamed on the sect has steadily worsened in recent months, with bomb blasts becoming more frequent and increasingly sophisticated and death tolls climbing, with at least 280 people killed since November.

There has been intense speculation over whether Boko Haram has links with outside extremist groups, including al Qaeda’s north African branch.

The group, whose name means “Western education is sin,” is believed to have a number of factions with varying aims.